I. Internet Protocol (IP) Service Priority
In an IPv4 header, there are 8 bits for representing a Type of Service (ToS), for 15 example, in a schematic diagram of the IPv4 header illustrated in FIG. 1 and a schematic diagram of the ToS field illustrated in FIG. 2; the first three bits in the ToS field represent an IP priority, which defines 8 values depicted in Table 1; and there are further a 4-bit ToS and 1 reserved bit in the ToS field, where the 4-bit ToS represents the lowest delay D, the highest throughput T, the highest reliability R and the lowest cost C.
TABLE 1IP priority valueIP priority name000Routine001Priority010Immediate011Flash100Flash Override101Critic110Internetwork Control111Network Control
As illustrated in FIG. 3 which is a schematic diagram of an IPv6 header, the IPv6 header includes two fields related to a Quality of Service (QoS), which are a Traffic Class (TC) and a Flow Label (FL), where the Traffic Class field is 8-bit, the function of which is the same as that of the Type of Service field in the IPv4 header, for identifying a traffic class; and the 20-bit Flow Label field identifies packets of the same traffic flow.
II. Evolved Packet System (EPS) Bearer Mapping Mechanism
A Policy Control and Charging (PCC) architecture maps a required QoS of a session service data flow at the application level to a required QoS for an access of an IP-Connectivity Access Network (IP-CAN) to a bearer-level service of a transport network to guarantee data transmission; and this is functionally embodied on an Application Function (AF), a Policy and Charging Rule Function (PCRF), a Policy and Charging Enforcement Function (PCEF) or a Bearer Binding and Event Report Function (BBERF) and a User Equipment (UE).
Particularly the AF transmits traffic information of media-plane parameters to the PCRF via an Rx interface in the form of signaling of an AF session; the PCRF maps the traffic information to authorized IP QoS parameters according to an operator policy, user subscription information, etc.; the PCRF issues a corresponding QoS policy to the PCEF of a Packet Data Network-Gateway (PDN-GW); the PCEF binds a bearer according to a PCC rule and maps these parameters to QoS parameters of the particular access via a Gx or Gxx interface, e.g., QoS parameters of the EPS bearer (e.g., a QoS Class Identifier (QCI), a Guaranteed Bit Rate (GBR), a Maximum Bit Rate (MBR), etc.).
Moreover the EPS bearer is the granularity, in which an Evolved Packet Core (EPC)/Evolved-Universal Terrestrial Radio Access Network (E-UTRAN) performs the QoS control, to enforce the same bearer-level packet forwarding strategy for traffic mapped to the same EPS bearer; an EPS bearer needs to traverse different network elements and interfaces and is mapped to a different underlying bearer on each of the interfaces; the respective network nodes are responsible for maintaining the identifiers of underlying bearers and their mutual binding relationship, where an eNodeB (i.e., a base station) creates binding between a radio bearer and an S1 bearer for mapping between the radio bearer and the S1 interface, and a Serving-Gateway (S-GW) creates binding between the S1 bearer and an S5/S8 bearer for mapping between the S1 bearer and the S5/S8 bearer; and finally data of the EPS bearer is concatenated over the radio bearer, the S1 bearer and the S5/S8 bearer to support connectivity traffic between the UE and a Packet Data Network (PDN) so as to guarantee the required QoS.
Each EPS bearer is associated with a so-called data packet Traffic Flow Template (TFT), where the TFT includes an uplink TFT and a downlink TFT respectively located at the UE side and the Gateway (GW). The TFT includes packet filter information, typically 5-tuple information including source and destination IP addresses, source and destination port numbers and a protocol number. A traffic data flow is mapped onto a corresponding EPS bearer by the GW or the UE side according to the packet filter information for the purpose of binding between the data flow and the EPS bearer.
III. Local IP Access Network Architecture
As illustrated in FIG. 4, in order to lower a cost at the network side and avoid congestion at the network side, an implementation at the network side relates to a direct access of the base station (or through the IP gateway) to the IP network, and in this architecture, the base station is the Access Point (AP); and unlike the traditional IP network, transmission of the base station to the UE is performed via an air interface by the base station transmitting an IP data packet to the UE via the air interface while guaranteeing the QoS required for the IP data packet via the air interface.
The inventors have identified during making of the invention at least the following problems in the prior art:
There has been absent in the prior art of a solution to direct mapping of a QoS required for an IP data packet to an air interface bearer, thus failing to satisfy the demand for transmission of the IP data packet.